Results Mixed With Home BP Monitoring

Action Points

A hypertension self-management program reduced systolic blood pressure in high-risk patients, including those with cardiovascular disease, diabetes, or chronic kidney disease.

Note that the study suggests that blood pressure self-monitoring and self-titration of hypertension drugs is feasible in patients at high risk for cardiovascular events, and could be an effective strategy for achieving significant reductions in blood pressure.

A hypertension self-management program reduced systolic blood pressure in high-risk patients, including those with cardiovascular disease, diabetes, or chronic kidney disease, according to British researchers.

When a group of high-risk patients (baseline blood pressure of at least 130/80 mm Hg) were randomized to blood pressure self-monitoring and self-titration or usual care, the intervention group had a clinically significant 9.2 mm Hg (95% CI 5.7-12.7) lower mean systolic blood pressure at a 12-month office visit, reported Richard J. McManus, PhD, from the University of Oxford, and colleagues.

Diastolic pressure was 3.4 mm Hg lower (95% CI 1.8-5.0) in the intervention group than the control group, and there was no significant difference in adverse symptoms related to treatment between the two groups, they wrote in the Journal of the American Medical Association.

"Based on systematic reviews of clinical outcome trials, the blood pressure difference observed in those self-managing would be expected to be associated with an approximate 30% reduction in stroke risk should it be sustained," the researchers wrote.

They concluded that blood pressure self-monitoring and self-titration of hypertension drugs is feasible in patients at high risk for cardiovascular events, and it could be an effective strategy for achieving significant reductions in blood pressure, as well as preventing strokes and heart attacks.

In an accompanying editorial, Peter M. Nilsson, MD, PhD, of Lund University in Lund, Sweden, stated that the findings represent "an important gain in knowledge about efficacy and safety of self-titration of antihypertensive drugs."

"What makes the study of particular clinical importance is the recruitment of patients who were at high risk of cardiovascular disease and the demonstration that the patient-centered technique was safe with no increase in adverse events compared with traditional treatment in a randomized setting," wrote Nilsson along with co-author Fredrik H. Nystrom, MD, PhD, of Linkoping University in Linkoping, Sweden.

McManus said the new research demonstrated that patients with hypertension and significant cardiovascular comorbidity can greatly reduce their blood pressure by self-monitoring, and following a pre-specified algorithm developed in consultation with a primary care physician.

He pointed out that even when hypertensive patients pay frequent visits to their healthcare providers, medications often aren't adjusted when blood pressure readings are not at target goals.

"We know that even in the best studies, action is taken only about half the time when a raised blood pressure is recorded," he said. "So our idea was to have a plan in place, and give patients more control so they can make a change when blood pressure is above a certain level."

Study Details

At entry into the study, the intervention patients met with their primary care physician to formulate a specific plan for adjusting their antihypertension treatment if their blood pressure remained high, McManus explained to MedPage Today.

During the 1-year trial, these patients were asked to take two daily morning blood pressure measurements the first week of every month, and adjust their treatment as previously agreed if weekly readings remained above target for 2 consecutive months.

The unblinded, randomized study originally included 552 patients who were at least 35-years-old with a history of cardiovascular disease, diabetes, stage 3 chronic kidney disease or coronary heart disease in addition to the aforementioned blood pressure readings.

Patients were excluded from the trial if they could not self-monitor, had blood pressure greater than 180/100 mm Hg, or if they were taking more than three antihypertensive medications, Patients who had experienced an acute cardiovascular event in the previous 3 months, or if they were being cared for by a specialist instead of a primary care physician, also were excluded.

Eligible patients were randomized between March and December of 2011 and were followed for 1 year.

Patients randomized to usual care booked an appointment for a routine blood pressure check and medication review with their family physician. After this, blood pressure measurements, targets, follow-up visits, and medication adjustments were at the discretion of the physician.

Patients randomized to self-management were trained to take their blood pressure using a validated monitor with self-titration of medication following a predetermined plan in two to three sessions lasting approximately 1 hour each. After training, the patients went to their family physicians to formulate an individualized three-step plan to either increase or add hypertensive medications if target goals were not met.

Patients took their blood pressure twice each morning for the first week of each month using simple color-coded instructions developed for the trial.

"Four or more blood pressure readings recorded during the measurement week for 2 consecutive months that were higher than target necessitated a change in medication pursuant to the predetermined plan," the researchers wrote. "Very high or very low readings (>180/100 mm Hg or <100 mm Hg systolic) required the participant to contact his/her practice."

During the study period, the office visit blood pressure measurement target was 130/80 mm Hg and the home measurement target was 120/75 mm Hg.

The patients attended two follow-up research clinics 6 and 12 months after randomization, and serial blood pressure measurements were performed using an electronic automated sphygmomanometer.

Primary outcomes data were available for 81% of the patients with most of the dropout occurred between baseline and 6 months; dropout was more common in the intervention group, the authors noted.

More Meds for Intervention Arm

There was little difference between the adjusted and unadjusted results, McManus and colleagues reported. After 12 months, there was a mean unadjusted systolic blood pressure difference of 9.2 mm Hg, and after multiple imputation for missing values the mean difference was 8.8 mm Hg (95% CI 4.9-12.7).

Prescription of antihypertensive medications increased in both groups, but the increase was significantly greater in the intervention group. The main changes seen were in the prescription of calcium channel blockers and thiazides, which significantly increased in the intervention group compared with the control group.

The researchers noted that more than double the number of patients randomized were agreeable to self-management, as measured by the number attending eligibility screening. Controlled blood pressure was the main reason these patients were not included in the trial.

"Taken together, for patients outside of a trial situation, we estimate that the intervention might be suitable for about 20% [of high-risk patients]," they wrote.

McManus said studies suggest that between 30% and 40% of high-risk patients on antihypertensive medications in the U.K. already monitor their own blood pressure, and at least a third of patients in the U.S. do.

Limitations

In addition to the higher than hoped for loss to follow-up, study limitations included the fact that patients in the study were mostly white (roughly 96% of both groups) and highly educated (roughly 67% of the usual care and 70% of the intervention group had a professional certification or college degree).

"No difference in blood pressure reduction from the intervention was seen between subgroups examined, but this may reflect inadequate statistical power," the authors wrote.

In their commentary, Nilsson and Nystrom noted that the failure to specifically address which medications are appropriate for self titration was a study limitation, as was the fact that less than 8% of the patients invited to participate in the study were randomized.

While the study "does not settle all questions regarding self-titration based on self-measurement, it is an important step toward adaption of treatment for patients who want to actively take part in their own risk-factor control," they wrote. "Future trials studying the effects of self-titration on cardiovascular events are needed."

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